| 摘要 |
The invention relates to semiconductor laser (10) which employs a 3-5 nitride material as a lasing medium. An example of such a 3-5 nitride material is Indium Gallium Nitride. The invention overcomes problems of existing short lived, broadband lasers in which it was not possible to reliably dope 3-5 nitrides, both p- and n- type. The invention relies upon the phenomenon of the relatively large band gap (6.28 eV) which is present in aluminium nitride (18). The atomic lattice structures of aluminium nitride (18) and Indium Gallium Nitride (16) are such that lasing can be made to occur within an Indium Gallium Nitride layer (16) which is supported (16) on a sapphire substrate (20) in which lattice mismatch is avoided by the use of an aluminium nitride layer (10). Donor electrons for recombination are provided by the Indium Gallium Nitride layer (16). The laser (10) may be directly electrically pumped or minority carriers may be obtained by using an incoherent light source (not shown). A Metal-Insulator-Semiconductor (MIS) structure is employed to create minority charge carriers in the semiconducting lasing medium. |
